Delft Department of Microelectronics, Faculty of Electronic, Mathematics and Information, Delft University of Technology, Delft 2628 CD, The Netherlands. Institute of Microelectronics, Tsinghua University, Beijing 100084, People's Republic of China. Changzhou Institute of Technology Research for Solid State Lighting, Changzhou 213161, People's Republic of China.
Nanotechnology. 2020 Jan 24;31(5):055501. doi: 10.1088/1361-6528/ab414e. Epub 2019 Sep 4.
Humidity sensors based on flexible sensitive nanomaterials are very attractive in noncontact healthcare monitoring. However, the existing humidity sensors have some shortcomings such as limited sensitivity, narrow relative humidity (RH) range, and a complex process. Herein, we show that a tin sulphide (SnS) nanoflakes-based sensor presents high humidity sensing behaviour both in rigid and flexible substrate. The sensing mechanism based on the Schottky nature of a SnS-metal contact endows the as-fabricated sensor with a high response of 2491000% towards a wide RH range from 3% RH to 99% RH. The response and recovery time of the sensor are 6 s and 4 s, respectively. Besides, the flexible SnS nanoflakes-based humidity sensor with a polyimide substrate can be well attached to the skin and exhibits stable humidity sensing performance in the natural flat state and under bending loading. Moreover, the first-principles analysis is performed to prove the high specificity of SnS to the moisture (HO) in the air. Benefiting from its promising advantages, we explore some application of the SnS nanoflakes-based sensors in detection of breathing patterns and non-contact finger tips sensing behaviour. The sensor can monitor the respiration pattern of a human being accurately, and recognize the movement of the fingertip speedily. This novel humidity sensor shows great promising application in physiological and physical monitoring, portable diagnosis system, and noncontact interface localization.
基于柔性敏感纳米材料的湿度传感器在非接触式医疗保健监测中非常有吸引力。然而，现有的湿度传感器存在一些缺点，如灵敏度有限、相对湿度（RH）范围窄和工艺复杂。在此，我们展示了一种基于硫化锡（SnS）纳米片的传感器在刚性和柔性基底上均具有出色的湿度传感性能。基于 SnS-金属接触肖特基性质的传感机制赋予所制备的传感器在从 3%RH 到 99%RH 的宽 RH 范围内具有 2491000%的高响应。传感器的响应和恢复时间分别为 6s 和 4s。此外，具有聚酰亚胺基底的柔性 SnS 纳米片基湿度传感器可以很好地贴合皮肤，并在自然平坦状态和弯曲加载下表现出稳定的湿度传感性能。此外，进行了第一性原理分析以证明 SnS 对空气中的水分（HO）具有高特异性。得益于其有前景的优势，我们探索了基于 SnS 纳米片的传感器在呼吸模式检测和非接触指尖传感行为中的一些应用。该传感器可以准确监测人体的呼吸模式，并快速识别指尖的运动。这种新型湿度传感器在生理和物理监测、便携式诊断系统和非接触式接口定位方面具有广阔的应用前景。
